diff --git a/xCAT-test/autotest/testcase/xcat-inventory/validatehelper b/xCAT-test/autotest/testcase/xcat-inventory/validatehelper
index 3910d5ec1..ab21b0cfa 100755
--- a/xCAT-test/autotest/testcase/xcat-inventory/validatehelper
+++ b/xCAT-test/autotest/testcase/xcat-inventory/validatehelper
@@ -1,191 +1,251 @@
-#!/usr/bin/bash
+#!/usr/bin/python
+from __future__ import print_function
 
-objtype=$1
-objname=$2
-attribute=$3
-attrvalue=$4
-tmpdir=$5
+import yaml
+import json
+import os 
+import re
+import sys
+import shutil
+import subprocess
 
 
-SOURCE="${BASH_SOURCE[0]}"
-while [ -h "$SOURCE" ]; do # resolve $SOURCE until the file is no longer a symlink
-  DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
-  SOURCE="$(readlink "$SOURCE")"
-  [[ $SOURCE != /* ]] && SOURCE="$DIR/$SOURCE" # if $SOURCE was a relative symlink, we need to resolve it relative to the path where the symlink file was located
-done
-DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
+#remove the dict entries whose value is null or ''
+def Util_rmnullindict(mydict):
+    for key in mydict.keys():
+        if isinstance(mydict[key],dict):
+            Util_rmnullindict(mydict[key])
+            if not mydict[key].keys():
+                del mydict[key]
+        else:
+            if not mydict[key]:
+                del mydict[key]
 
 
-function usage {
-    echo "Usage:"
-    echo "${BASH_SOURCE[0]} [ OBJTYPE OBJNAME ATTRIBUTE ATTRVALUE TMPDIR]"
-}
+# get the dict value mydict[a][b][c] with key path a.b.c
+def Util_getdictval(mydict,keystr):
+    if not  isinstance(mydict,dict):
+        return None
+    dictkeyregex=re.compile("([^\.]+)\.?(\S+)*")
+    result=re.findall(dictkeyregex,keystr)
+    if result:
+        (key,remdkey)=result[0]
+        if key not in mydict.keys():
+            return None
+        if remdkey:
+            return Util_getdictval(mydict[key],remdkey)
+        else:
+            return mydict[key]
 
-echo objtype=\"${objtype}\"
-echo objname=\"${objname}\"
-echo attribute=\"${attribute}\"
-echo attrvalue=\"${attrvalue}\"
-echo tmpdir=\"${tmpdir}\"
+# get the dict value mydict[a][b][c] with key path a.b.c
+def Util_setdictval(mydict,keystr,value):
+    dictkeyregex=re.compile("([^\.]+)\.?(\S+)*")
+    result=re.findall(dictkeyregex,keystr)
+    if result:
+        (key,remdkey)=result[0]
+        if remdkey:
+            if key not in mydict.keys():
+                mydict[key]={}
+            Util_setdictval(mydict[key],remdkey,value)
+        else:
+            mydict[key]=value
+
+def GetAttrInFile(fpath,objtype,objname,attrpath):
+    f=open(fpath,'r')
+    try:
+        objdict=json.loads(f)
+    except TypeError,ValueError:
+        try:
+            objdict=yaml.load(f)
+        except Exception,e:
+            raise Exception("Error: cannot open file "+fpath+"! "+str(e))
+
+    f.close()
+    myattrpath=objtype+"."+objname+"."+attrpath
+    myvalue=Util_getdictval(objdict,myattrpath)
+    if isinstance(myvalue,list):
+        myvalue=myvalue[0]
+    return myvalue
+
+def runCommand(cmd, env=None):
+    """ Run one command only, when you don't want to bother setting up
+        the Popen stuff.
+    """
+    print('Running command: %s' %cmd)
+    try:
+        p = subprocess.Popen(cmd,
+                             env=env,
+                             shell=True,
+                             stdout=subprocess.PIPE,
+                             stderr=subprocess.PIPE
+                            )
+        out, err = p.communicate()
+    except OSError,e:
+        print('RunCommand failed due to OSError %s' % e)
+    if p.returncode:
+        print('Command %s failed with return code %d : %s' % (cmd , p.returncode, err))
+    print(out)
+    print(err)
+    return p.returncode 
+  
+
+def UpdateAttrInFile(fpath,fformat,objtype,objname,attrpath,value):
+    f=open(fpath,'r')
+    try:
+        objdict=json.loads(f)
+    except TypeError,ValueError:
+        try:
+            objdict=yaml.load(f)
+        except Exception,e:
+            raise Exception("Error: cannot open file "+fpath+"! "+str(e))
+
+    f.close()
+    myattrpath=objtype+"."+objname+"."+attrpath
+    if value == "":
+        Util_setdictval(objdict,myattrpath,"")
+        Util_rmnullindict(objdict)
+    else:
+        origobjdict=Util_getdictval(objdict,myattrpath)
+        if isinstance(origobjdict,list) and not isinstance(value,list):
+            newvalue=[value]
+        else:
+            newvalue=value
+        Util_setdictval(objdict,myattrpath,newvalue)
+    f=open(fpath,'w') 
+    if fformat  == "yaml":
+        print(yaml.dump(objdict,default_flow_style=False),file=f)
+    elif fformat  == "json":
+        print(json.dumps(objdict, sort_keys=True, indent=4, separators=(',', ': ')),file=f)
+    f.close()
+
+def removeobj(objtype,objname):
+    print("removing existing \""+objtype+"\" type object \""+objname+"\" from xCAT\n")
+    if str(objtype) in ('node','osimage','network','site','route','zone','policy'):
+        runCommand("rmdef -t "+objtype+" -o "+objname) 
+    elif str(objtype) in ('passwd'):
+        runCommand("tabch -d key="+objname+" passwd")
+
+def Usage():
+    print("Usage:\n")
+    print(sys.argv[0]+" [OBJTYPE OBJNAME ATTRIBUTE ATTRVALUE TMPDIR]")
+
+if len(sys.argv) < 6:
+    Usage()
+    exit(1)
+   
+
+objtype=str(sys.argv[1])
+objname=str(sys.argv[2])
+attribute=str(sys.argv[3])
+attrvalue=str(sys.argv[4])
+tmpdir=str(sys.argv[5])
+print("objtype=%s\nobjname=%s\nattribute=%s\nattrvalue=%s\ntmpdir=%s\n"%(objtype,objname,attribute,attrvalue,tmpdir))
+
+if os.path.exists(tmpdir):
+    runCommand("rm -rf "+tmpdir)
+
+os.mkdir(tmpdir)
+
+print("Temporary directory to hold intermediate files: "+tmpdir+"\n")
+
+curdir=os.path.split(os.path.realpath(sys.argv[0]))[0]
+yamldeftmpl=curdir+"/templates/"+objtype+'.yaml'
+jsondeftmpl=curdir+"/templates/"+objtype+'.json'
+yamldef=tmpdir+"/"+objtype+'.yaml'
+jsondef=tmpdir+"/"+objtype+'.json'
+yamldefout=tmpdir+"/"+objtype+'.out.yaml'
+jsondefout=tmpdir+"/"+objtype+'.out.json'
+
+shutil.copyfile(yamldeftmpl,yamldef)
+shutil.copyfile(jsondeftmpl,jsondef)
+
+rcfinal=0
+rcyaml=0
+rcjson=0
+rc=0
+
+UpdateAttrInFile(yamldef,'yaml',objtype,objname,attribute,attrvalue)
+print("=================the inventory file to import: "+yamldef+"=====================\n")
+runCommand("cat "+yamldef)
+print("===============================================================================\n")
 
 
-if [ -z "$objtype" ] || [ -z "$objname" ] || [ -z "$attribute" ] || [ -z "$tmpdir" ]; then
-    usage
-    exit 1
-fi
+print("import the inventory file "+yamldef+"\n") 
+rc=runCommand("xcat-inventory import -t "+objtype+" -o "+objname+" -f "+yamldef)
+if rc !=0:
+    print("failed to import the inventory file "+yamldef)
+    rcyaml=1
+else:
+    print("the inventory file "+yamldef+" imported successfully\n")
+    print("export the \""+objtype+"\" type object \""+objname+"\" just imported\n")
+    rc=runCommand("xcat-inventory export -t "+objtype+" -o "+objname+" --format=yaml 1>"+yamldefout)
+    if rc!=0:
+        print("failed to export the \""+objtype+"\" type object \""+objname+"\"\n") 
+        rcyaml=1
+    else:
+        print("==============the exported inventory file "+yamldefout+"======================\n")
+        runCommand("cat "+yamldefout)
+        print("===========================================================================\n")
+        myattrvalue=GetAttrInFile(yamldefout,objtype,objname,attribute)
+        if attrvalue == '':
+            if myattrvalue is not None:
+                rcyaml=1
+        else:
+            if myattrvalue != attrvalue:
+                rcyaml=1           
 
-RETCODE_YAML=0
-RETCODE_JSON=0
+if rcyaml == 0:
+    print("yaml validation passed\n")
+else:
+    print("yaml validation failed\n")
 
-[ -e "$tmpdir" ] || rm -rf $tmpdir
-mkdir -p $tmpdir
-echo "Temporary directory to hold intermediate files: $tmpdir"
+removeobj(objtype,objname)
 
-cp ${DIR}/templates/${objtype}.json ${tmpdir}/
-cp ${DIR}/templates/${objtype}.yaml ${tmpdir}/
-
-#the intermediate inventory files to import
-yamldef="${tmpdir}/${objtype}.yaml"
-jsondef="${tmpdir}/${objtype}.json"
-
-#the intermediate inventory files exported
-yamldefout="${tmpdir}/${objtype}.out.yaml"
-jsondefout="${tmpdir}/${objtype}.out.json"
-
-echo "removing existing \"$objtype\" type object \"$objname\" from xCAT"
-echo "osimage node network site route zone policy "|grep -q -w "$objtype"
-if [ $? -eq 0 ];then
-    rmdef -t $objtype -o $objname
-fi
-if [ "$objtype" = "passwd" ];then
-    tabch -d key=$objname passwd
-fi
-
-#substitute the attribute value in inventory files
-if [ ${#attrvalue} -ne 0 ];then
-    sed -i -E -e "s/^(\s*["'"'"']?$attribute["'"'"']?:\s*["'"'"']?)[^'"'"'"]*(["'"'"']?[,]?\s*)$/\1$attrvalue\2/g" $yamldef
-else
-    sed -i -e "/^\s*["'"'"']*$attribute["'"'"']*:/d" $yamldef
-fi
-
-echo "=================the inventory file to import: ${yamldef}====================="
-cat $yamldef
-echo "=============================================================================="
+UpdateAttrInFile(jsondef,'json',objtype,objname,attribute,attrvalue)
+print("=================the inventory file to import: "+jsondef+"=====================\n")
+runCommand("cat "+jsondef)
+print("===============================================================================\n")
 
 
-echo "import the inventory file $yamldef "
-xcat-inventory import -t $objtype -o $objname -f $yamldef 
-if [ $? -ne 0 ];then
-    echo "failed to import the inventory file $yamldef"
-    RETCODE_YAML=1
-else
-    echo "the inventory file $yamldef imported successfully"
-    echo "export the \"$objtype\" type object \"$objname\" just imported"
-    xcat-inventory export -t $objtype -o $objname --format=yaml 1>$yamldefout
-    if [ $? -ne 0 ];then
-        echo "failed to export the \"$objtype\" type object \"$objname\""
-        RETCODE_YAML=1
-    else
-        echo "the inventory data of the \"$objtype\" type object \"$objname\" exported to $yamldefout"
-        echo "==============the exported inventory file $yamldefout======================"
-        cat $yamldefout
-        echo "==========================================================================="
-        echo "make sure the attribute  $attribute is imported and exported successfully"
-        if [ -n "$attrvalue" ]; then
-            cat $yamldefout|grep -w "$attribute"|grep -q -w "$attrvalue"
-            if [ $? -ne 0 ];then
-                RETCODE_YAML=1 
-            fi       
-        else
-            cat $yamldefout|grep -q -w "$attribute"
-            if [ $? -eq 0 ];then
-                RETCODE_YAML=1 
-            fi       
-        fi
+print("import the inventory file "+jsondef+"\n") 
+rc=runCommand("xcat-inventory import -t "+objtype+" -o "+objname+" -f "+jsondef)
+print("rc="+str(rc))
+if rc !=0:
+    print("failed to import the inventory file "+jsondef)
+    rcjson=1
+else:
+    print("the inventory file "+jsondef+" imported successfully\n")
+    print("export the \""+objtype+"\" type object \""+objname+"\" just imported\n")
+    rc=runCommand("xcat-inventory export -t "+objtype+" -o "+objname+" --format=json 1>"+jsondefout)
+    if rc!=0:
+        print("failed to export the \""+objtype+"\" type object \""+objname+"\"\n") 
+        rcjson=1
+    else:
+        print("==============the exported inventory file "+jsondefout+"======================\n")
+        runCommand("cat "+jsondefout)
+        print("===========================================================================\n")
+        myattrvalue=GetAttrInFile(jsondefout,objtype,objname,attribute)
+        if attrvalue == '':
+            if myattrvalue is not None:
+                rcjson=1
+        else:
+            if myattrvalue != attrvalue:
+                rcjson=1           
+
+if rcjson ==0:
+    print("json validation passed\n")
+else:
+    print("json validation failed\n")
+
+removeobj(objtype,objname)
+
+if rcjson !=0 or rcyaml!=0:
+   rcfinal=1
+
+print("remove intermediate directory "+tmpdir)
+if os.path.exists(tmpdir):
+    runCommand("rm -rf "+tmpdir)
+
+exit(rcfinal)
 
 
-    fi
-fi
-
-if [ $RETCODE_YAML -eq 0 ]; then  
-    echo "yaml validation passed"
-else
-    echo "yaml validation failed"
-fi
-
-echo "removing existing \"$objtype\" type object \"$objname\" from xCAT"
-echo "osimage node network site route zone policy "|grep -q -w "$objtype"
-if [ $? -eq 0 ];then
-    rmdef -t $objtype -o $objname
-fi
-
-if [ "$objtype" = "passwd" ];then
-    tabch -d key=$objname passwd
-fi
-
-
-if [ ${#attrvalue} -ne 0 ];then
-    sed -i -E -e "s/^(\s*["'"'"']?$attribute["'"'"']?:\s*["'"'"']?)[^'"'"'"]*(["'"'"']?[,]?\s*)$/\1$attrvalue\2/g" $jsondef
-else
-    sed -i -e "/^\s*["'"'"']*$attribute["'"'"']*:/d" $jsondef
-fi
-
-echo "=================the inventory file to import: ${jsondef}====================="
-cat $jsondef
-echo "=============================================================================="
-
-echo "import the inventory file $jsondef "
-xcat-inventory import -t $objtype -o $objname -f $jsondef 
-if [ $? -ne 0 ];then
-    echo "failed to import the inventory file $jsondef"
-    RETCODE_JSON=1
-else
-    xcat-inventory export -t $objtype -o $objname 1>$jsondefout 
-    if [ $? -ne 0 ];then
-    echo "the inventory file $jsondef imported successfully"
-    echo "export the \"$objtype\" type object \"$objname\" just imported"
-        RETCODE_JSON=1
-    else
-        echo "the inventory data of the \"$objtype\" type object \"$objname\" exported to $jsondefout"
-        echo "==============the exported inventory file $jsondefout======================"   
-        cat $jsondefout
-        echo "==========================================================================="
-        echo "make sure the attribute  $attribute is imported and exported successfully"
-        if [ -n "$attrvalue" ]; then
-            cat $jsondefout|grep -w "$attribute"|grep -q -w "$attrvalue"
-            if [ $? -ne 0 ];then
-                RETCODE_JSON=1 
-            fi       
-        else
-            cat $jsondefout|grep -q -w "$attribute"
-            if [ $? -eq 0 ];then
-                RETCODE_JSON=1 
-            fi       
-        fi
-
-    fi
-fi
-
-if [ $RETCODE_JSON -eq 0 ]; then  
-    echo "json validation passed"
-else
-    echo "json validation failed"
-fi
-
-
-echo "osimage node network site route zone policy "|grep -q -w "$objtype"
-if [ $? -eq 0 ];then
-    rmdef -t $objtype -o $objname
-fi
-
-if [ "$objtype" = "passwd" ];then
-    tabch -d key=$objname passwd
-fi
-
-echo "remove intermediate directory $tmpdir"
-[ -e "$tmpdir" ] || rm -rf $tmpdir
-
-if [ $RETCODE_YAML -ne 0 ] || [ $RETCODE_JSON -ne 0  ]; then
-    exit 1
-fi 
-
-exit 0